Percentage Calculator

Calculate percentages, percentage changes, and find values from percentage relationships with step-by-step explanations.

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What is X% of Y?

What is % of = ?

X is what % of Y?

is what % of = ?%

X is Y% of what?

is % of ?

Percentage Increase/Decrease

From to = ?%
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How to Use Percentage Calculator

How to Use the Percentage Calculator

  1. Select calculation type: Choose which type of percentage calculation you need from the dropdown menu.
  2. Enter values: Fill in the numbers required for your chosen calculation type.
  3. Click Calculate: Press the Calculate button to see your result.
  4. View the solution: See both the answer and the step-by-step calculation breakdown.
  5. Copy or reset: Copy your result or reset to perform another calculation.

Example Calculations

  • What is 15% of 80? → 80 × 0.15 = 12
  • 25 is what % of 200? → (25 ÷ 200) × 100 = 12.5%
  • Increase from 50 to 65: → ((65-50) ÷ 50) × 100 = 30% increase
  • $80 with 20% tip: → 80 + (80 × 0.20) = $96
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Features

  • Multiple calculation types in one tool
  • Percentage increase and decrease calculator
  • Step-by-step solution explanations
  • Decimal precision options (2-6 places)
  • Common percentage quick buttons
  • Works with decimals and large numbers
  • Reverse percentage calculations
  • Percentage difference calculator
  • Copy result to clipboard
  • Mobile-friendly interface
  • No registration required
  • Instant calculations
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About Percentage Calculator

Percentages appear everywhere in daily life—discounts, tips, taxes, interest rates, exam scores, and statistical data. Our Percentage Calculator handles all common percentage operations with clear explanations of the math behind each result.

Calculation Types

  • What is X% of Y: Find a percentage of any number (e.g., 15% of 200 = 30)
  • X is what % of Y: Express one number as a percentage of another (e.g., 30 is 15% of 200)
  • Percentage Change: Calculate increase or decrease between two values
  • Add/Subtract Percentage: Apply percentage changes to values (e.g., 200 + 15% = 230)
  • Find Original Value: Work backwards from a percentage result

Understanding Percentage Change

Percentage change measures how much a value has grown or shrunk relative to its starting point. The formula is: ((New - Old) / Old) × 100. A stock rising from $50 to $75 shows a 50% increase, not 25%, because we measure against the original $50. This distinction matters for financial and statistical accuracy.

Common Errors Avoided

Adding percentages directly often produces wrong results—a 50% increase followed by a 50% decrease doesn't return to the original value. Confusing "percentage points" with "percent change" leads to misinterpretation. Our calculator provides precise results while explaining the underlying mathematics.

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Frequently Asked Questions

How do I calculate a percentage of a number?
To find X% of Y, multiply Y by X/100. For example, 15% of 200 = 200 × 0.15 = 30. Our calculator does this instantly - enter the percentage and the number, and get your result. You can also calculate what percentage one number is of another, or find the original number from a percentage.
What is the formula for percentage increase?
Percentage increase = ((New Value - Original Value) / Original Value) × 100. For example, if a price goes from $50 to $65: (65-50)/50 × 100 = 30% increase. Our calculator handles increases, decreases, and can reverse-calculate original values from percentage changes.
How do I calculate percentage decrease?
Percentage decrease = ((Original Value - New Value) / Original Value) × 100. For example, a price drop from $80 to $60: (80-60)/80 × 100 = 25% decrease. The formula is similar to increase but subtracts in the opposite order. Our tool calculates both automatically.
What is X% of Y? (Common calculations)
We provide quick calculations for common percentages: 10% = divide by 10, 20% = divide by 5, 25% = divide by 4, 50% = divide by 2. For tips: 15% = 10% + half of 10%, 20% = double 10%. Our calculator handles any percentage instantly, including decimals like 7.5% or 33.33%.
How do I find what percentage one number is of another?
To find what percent A is of B: (A / B) × 100. For example, 30 is what percent of 150? (30/150) × 100 = 20%. This is useful for calculating test scores, completion rates, market share, and similar comparisons. Enter both numbers in our tool to get the percentage instantly.
Can I calculate reverse percentages?
Yes! If you know the result after a percentage change, you can find the original. For example, if $75 represents 125% of the original (after 25% increase): $75 / 1.25 = $60 original. Our calculator has a dedicated reverse percentage mode for these calculations.